This circuit was found in an American medical documentation from 1970. The circuit rejects the 60 Hz noise pickup and generates 2.5 Hz signals. Equivalent components can be tested.
This circuit was found in a Popular Electronics from the 90's. The output signal can be applied to a...
This circuit, which appears at other points on this site, can be designed with both 4011 and 4001...
This 40-second timer uses common components. The output can be used to excite a power stage. With...